The complexity of medical equipment necessitates annual testing to assure correct performance. In many cases these tests need to be tailored to a specific brand and model. The tests need to be less time consuming than a full calibration, but detailed enough to test important -safety and efficacy features. In compliance with new standards required of the Clinical Center we have written testing procedures that give medical staff assurance that medical equipment works properly. These tests reflect Clinical Center experience with medical equipment as well as manufacturers' recommendations. For example, battery powered defibrillators are tested on a weekly basis using an abbreviated testing procedure to assure batteries are of sufficient capacity for emergency use. They are also tested on an annual basis to assure compliance with most manufacturer's specifications. The procedures are designed to be used by novice technicians under the direction of an experienced technician.